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Old 01-01-2007, 09:09 PM
James Pierson James Pierson is offline
Master Modeler
Join Date: Dec 2005
Location: Washington State
Posts: 654
Question Huh??

Craig said,
I just created a new simulation file of the Andromeda, with the addition of two CR-713 centering rings mounted at the openings of the shrouds. This will block off the flow of air through the shrouds and prevent them from acting as ringfins. The first indication that this may be important is the altitude gained: 910' versus 881' over the non-plugged non-ringfin simulation. The second indication that something changed was the stability margin; when using a C6-5 the margin dropped to 0.74. A ballast weight of 0.10 oz was added to the back of the nose cone, and the margin came back up to 1.13.

This leads me to suspect that just maybe Rocksim is not accounting for airflow through both the Ringfins and Tubefins. I wonder?? It may be the extra wieght of the added CR-713 that accounts for the altitude change.

James Pierson
NAR# 77907
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